Various methods of fabricating turbomachinery parts, including impeller blades, diaphragms, and guide vanes, are known. Typically, such parts are assembled from smaller forged and machined parts. The smaller parts are machined to tight tolerances and then fixed together such as by welding, brazing, or e-brazing.
However, such machining and fixing processes are time-intensive and costly, and typically yield turbomachinery parts that are comprised of multiple distinct pieces. Having these multiple distinct pieces necessitates joints where stress can be concentrated, which can lead to deformation or even failure, thereby reducing the effective life of the turbomachinery part.
One way of overcoming this is by casting the part as a whole. However, casting is typically not useful in parts requiring tight tolerances. Further, the finished casting surface can be rough compared to machined surfaces. In parts that manipulate high velocity and/or pressure fluid, the roughness of the surface and the tolerances are critical to efficiency, such that casting is not typically useful for many turbomachine parts. What is needed, therefore, is a method of making turbomachine parts that does not suffer from the stress, time-consumption, and/or other drawbacks of the multiple-piece assemblies, or the inaccuracy and/or other drawbacks of conventional casting methods.